If you're flying to California to visit
Disneyland, be sure to consider alternate airports in the LA area. John Wayne Orange County Airport (SNA), served by most major airlines, is the closest airport to Disneyland, and it's a very pleasant airport. Long Beach (LGB), served primarily by JetBlue, is another good choice. Los Angeles International (LAX), a huge airport, sometimes has intense fare competition, and sometimes it doesn't. Also, check the fares into little-known Ontario Airport (ONT). At one time or another, any of these airports could have the lowest prices.
If you're willing to drive further (around 100 miles each way), you should also check San Diego (SAN) -- especially if you also want to stay in San Diego County for a few days to visit some of San Diego's wonderful attractions.
Finally, unless you traveling around the Christmas holidays, don't rush into buying your tickets. Sign up for fare trackers at airline websites and travel websites. Watch for sales and fare wars. Then grab tickets that provide the right combination of price and convenience. Don't worry about getting the very lowest fare ever offered, but don't rush into paying too much either.